1. Field of the Invention
The field of the invention is automatic coin dispensing machines.
2. Description of the Prior Art
Until recent years coin dispensing machines have been constructed as electromechanical devices. Such machines included a keyboard, a number of electromechanical switches actuated through the keyboard, a coin magazine with a plurality of coin ejector solenoids having a finger that could be aligned to kick a coin out of a respective channel, and a motor for driving these coin dispensing fingers to kick out the required amount of change to a coin chute. The operator of these coin dispensers was required to "key in" either the amount of change to be dispensed, or in devices with simple calculating ability, was required to key the cents to be tendered which the coin dispenser subtracted from $1.00 to arrive at the change figure that was dispensed. These earlier devices are distinguishable from cash registers which had much greater calculating capability, but did not dispense change automatically.
Electromechanical cash registers have for the most part been replaced by smaller, lighter electronic machines incorporating digital circuitry. In some instances, the calculating and record-keeping functions of such cash registers have been expanded by substituting point of sale computer terminals such as disclosed in Asbo, et al., U.S. Pat. No. 3,631,403, issued Dec. 28, 1971. Where such expanded capability is not necessary, it is more economical to replace such cash registers with automatic coin dispensers with some calculating capability. These coin dispensers can also serve as peripheral units, which can be connected through cables to an electronic cash register.
Electronic coin dispensers still utilize some electromechanical elements such as coin ejector solenoids and a payment solenoid to dispense coins. It is also desirable to provide a printer, which is another electromechanical device to be interfaced with the digital electronics of a modern coin dispenser. Various technical problems are presented in interfacting digital control circuitry with such electromechanical devices. For example, the voltage to the print head must be carefully controlled to prevent the head from overheating, and the roll carrying the record-keeping tape must be operable to prevent slack from developing and to provide sufficient space between groups of numbers representing different transactions. As another example of an interface problem, a minimum time arrival must be maintained between payment operations to allow the electromechanical elements to recover after each operation.